hjelte



(No Model.) 3 Sheets-Sheet 1.

A. HJEL'TE.

STEAM ENGINE.

nted'Sept. 9, 1890.

3 Sheets-Sheefi '3.

(No Model.)

A. HJELTE. STEAM ENGINE.

m g u w, r 9, ii t p d W 8 W Q t n V q 5 t. M w A 6/ ,A v 4% h M M 4 Z Q [X F 9 m my 1 \Z 2% m 4%; 7 M W W a H w 7.. 7 Y W I m w w 9 a N W% UNITED S ATES PATENT OF ICE.

ADOLF HJEL'IE, OF CHICAGO, ILLINOIS, ASSIGNOR TO HIMSELF, JOHN P. JOHNSON, AND PETER A. LIND, ALL OF SAME PLACE.

STEAM-ENGINE.

SPECIFICATION forming part of Letters Patent No. 435,970, dated September 9, 1890.

Application filed June 17, 1890. Serial No. 355,787. (No model.)

To all whom it may concern.-

Be it known that I, ADOLF HJELTE, residing in Chicago, county of Cook, State of Illinois, and a subject of the King of Sweden, have invented a new and useful Improvement in Steam-Engines, of which the following is a specification, reference being had to the accompanying drawings, in which- Figure 1 is a top or plan view. Fig. 2 is a longitudinal section on line 2 2 of Fig. 1, and Fig. 3 is a cross-section on line 3 3 of Fig. 1.

This invention relates to steam-engines, and particulary to the class known as compound engines. a

The objects of this invention are to provide a compound engine which shall be compact and simple in construction, to provide an improved valve for operating the engine, and to provide other improvements hereinafter more specifically set forth, and pointed out in the claims. I accomplish these objects as illustrated in the drawings, and as hereinafter described.

In the drawings, A represents the bed-plate of the engine, which is made in suitable form to support the parts.

B is the cylinder, which may be cast or formed integral with the bed-plate A. This cylinder B is provided with a high-pressure chamber C, a medium-pressure chamber D, and alow-pressure chamber E. The mediumpressure chamber D is, in fact, a continuation of the chamber C, while the low-pressure chamber E is of greater diameter than the chambers C D.

F is a piston which is provided with a head fin the high-pressure chamber C and a head d in the medium-pressure chamber D.

G is a second piston, which is provided with a head d in the medium-pressure chamber D and a larger head e in the low-pressure chamber E.

The piston F is provided with a rod H and the piston G is provided with a rod J. The rod H is tubular, so that the rod J can slide longitudinally through it. The end of the cylinder B is provided with a head and stuffing-box as usual. The piston H is provided with a head h, to which is connected a pitman h, which is connected with a crank la in a crank-shaft K, and the piston-rod J is provided with a head j, which is connected by a pitman j with a crank in the crank-shaft K.

L is a rotary valve which is located in a suitable valve-chest L. There is a steampassage Zbetween the valve L and valve-chest L, as shown in Fig. 2. The valve L is pro-' vided with three slides M in the form shown in Fig. 3, which are pressed outwardly across the steam-passage Z by means of springs m. The valve-chest L is provided with a cam m, which is arranged to force the slides M in wardly, and with a cut-off m.

N is a rocking valve, which is located in a chest N, preferably above and integral with the chest L. The valve N is provided with a chamber 02, extending nearly its entire circumference, and a chamber at, which extends longitudinally, as shown in Figs. 2 and 3. This valve is also provided with a cut-off 0. Live steam is admitted to the chamber '17, from the boiler, and the exhaust-steam is exhausted through the chamber it.

0 o are two ports between the valve-chest L and the valve-chest N. When the valve N is in the position shown in Fig. 2, live steam will be admitted to the passage Z through the port 0 and the exhaust-steam will be exhausted through the port 0 into the chamber n of the valve N. A port a is provided, which leads from the passage Zinto the high-pressure chamber C. Aport b is provided, which leads from the passagel into the chamber D, and a port 0 is provided, which leads from the passage Z to the low-pressure chamber E. The ports 0 o are equidistant from the cut-off m", and in a valve employing three slides M the distance between the ports 0 0 is one-third of the outer circumference of the passage Z. The portb is one-third of the exterior circumference of the passagel from each of the ports 0 0', and the ports a and c are equally distant from the port b and one-third of the circumference of the passage 1 from each other.

P is a gear-wheel mount-ed upon the stem of the valve L, and P is a gear-wheel mounted upon the shaft K. When a valve with three slides M is used, the wheel P must be three times the diameter of the wheel P-that is,

the valve L must make one rotation while the shaft Kis making three rotations.

WVhen steam is admitted through the port 0 into the passage l,it will pass into the highpressure chamber 0 and drive the piston F toward the center of the cylinder. The piston G will also be driven toward the center, as hereinafter described. IVhile the steam is passing from the port 0 through the passage Zto the port 0. one slide M of the valve L will pass from the port a to the port I) and the following slide will pass from the cut-off O to the port 0. The steam will therefore be admitted at high pressure into the chamber 0. When the slides M reach the position shown in Fig. 2, the second slide M will cut off the passage Z between the port a and the port 0 and open the passage between the ports a and Z). This will permit the steam in the chamber 0 to pass into the chamber D, and the piston-heads (Z (Z being greater in area than the piston-head f the piston F and piston G will be driven outwardly or apart. \Vhen one slide passes the port a, the following slide will have passed the port 0., thereby permitting the steam to pass from the chamber D to the low-pressure chamber E. The piston-head e in the low-pressure chamber is greater in area than the piston-head in the chamberD, so that the piston Gwill be driven inwardly. \Vhen steam is passing from the port a to the port Z), the exhaust-port 0 will be open, thereby permitting the discharge of the steam from the low-pressure chamber E to the passage Z.

It will be understood that when steam at high pressure is being admitted through the port 0, passage Z, and port a to the highpressure cylinder 0 the steam at medium pressure in the chamber D will be admitted through the port Z), passage Z, and port 0 into the low-pressure chamber E, thereby simultaneously driving the pistons F and G t0- ward each other; and when steam is being admitted from the high-pressi'ire chamber 0 into the medium-pressure chamber D the port 0 will be cut off by one slide M and the exhaust-port 0 will be in connection with the port 0 through the passage Z, so that the pis tons F and G will be driven toward each other by high and low pressure and separated by medium pressure. The steam admitted into the passage Z from the port 0 will drive the slide M and the valve 0 from the time the slide M passes the port 0 until it reaches the port a, and the slides M will also be driven forward by the difference in pressure of the steam on their opposite sides after passing the ports a, l), and 0, so that the valve L will itself be driven by the steam passing through it. In an engine which I have constructed on a scale four times the scale of the drawings the valve L alone has developed a power equal to two-horse power.

In order to balance the pressure on the slide M, I provide a small steam-passage p in advance of each slide, which admits steam into the recess, which contains a spring on. This steam-passage 13 receives steam from the port 0 before the slide M reaches the port 0, thereby balancing the slide. The steam in the passage 19 and recess in rear of the slide M can escape when the slide M is pressed inwardly by the cam on, as shown in Fig. 2.

The engine which I have shown is particularly designed to be used as a stationary eugine, and the connections of the pitmen h j is only one of many forms which I may use. I have shown a guide Q for guiding the crossheads to which the pitmenj' and h are pivoted. I do not limit my invention to the construction shown.

For certain uses the engine must be reversed. In order to reverse my engine the valve N may be shifted, bringing the opening a in communication with the port 0 and the port 0 in communication with the passage a. This will cause the high-pressure steam to rotate the valve L in the opposite direction, and the chamber E will then be the high-pressure chamber and the chamber 0 cannot be used. I therefore provide an exhaust-portR between the port a and the port 0. I provide this port and its steam-pipe with a valve 0'. As shown in Fig. l, I connect the stem 7' of the valve 7* with the valve-stem of the valve N by means of geared segments 3.

I do not limit my invention to the use of this device, as many other forms of connect ing devices may be used. The essential fea ture is, however, that the valve-stem 4" be connected with the stem of the valve N, so that when the valve N is shifted to reverse the engine the port R will be opened.

It will be understood that my engine is to be packed and provided with stuffing-boxes as may be necessary. The engine above described is exceedingly compact and produces large power from the steam used, for the rea son that the steam in use is expanded three times, and also a considerable amount of power is obtained from the rotary valve.

I do not limit my invention to a rotary valve having three slides M, as the number of slides may be varied; but three slides in use are found more convenient and practical.

As shown, both piston-rods II and J extend. through the samehead of the cylinder; but it is evident that the rod J can be passed through the head at the opposite end and connected with a second shaft.

lVhat I claim as new, and desire to secure by Letters Patent, is- V 1. In a steam-engine, the combination of a cylinder comprising three chambers C, D, and I], with two pistons moving in opposite directions, a valve and ports for admitting steam to the chamber 0, from chamber C to chamber D, and from chamber D to chamber E, and for exhausting the steam from the chamber E,substantially as and for the purpose specified.

2. In a steam-engine, the combination of a steanrcylinder comprising three chambers C,

IIS

provided with passages 'n 'n, substantially as I specified.

4. In a steam-engine, the combination, with a steam-cylinder comprising three chambers and having ports a b c, and a valve-chest L,

provided with ports 0 0, of a rotary valve L, provided With spring-slides M, and a cut-01f m, substantially as and for the purpose specified.

5. The combination of a steam-cylinder comprising chambers O, D, and E, and ports a b c, and pistons F and G, with a valve-chest L, rotary valve L, and exhaust-port R, pro

vided With a valve n, whereby the engine may 2 5 be reversed, substantially as specified.

ADOLF HJELTE. Witnesses:

HARRY T. J ONES, JOHN L. JACKSON. 

